Fluid metering or applicator rollers, commonly referred to as "anilox rollers", are used in the printing industry to transfer measured amounts of printing ink or a protective and/or decorative liquid coating to a plate cylinder or to a blanket cylinder. The surface of the applicator roller is engraved with an array of closely spaced, shallow depressions referred to as "cells". Ink or liquid coating material flows into the cells as the anilox roller turns within a reservoir. The engraved transfer surface of the applicator roller is scraped with a doctor blade to remove excess ink or liquid coating material. The ink or liquid coating material remaining on the anilox roller is contained within the cells. The plate cylinder or blanket cylinder transfers ink or liquid coating material from the cells of the anilox roller over all or a portion of the surface of printed sheets or a web of material, either plastic or paper, onto which the desired image is imprinted.
The anilox roller has a cylindrical surface and may be constructed in various diameters and lengths containing cells of various sizes and shapes. The volumetric capacity of an anilox roller is established during manufacturing and is dependent upon the selection of cell size, shape and number of cells per unit area. Depending upon the intended application, the cell pattern may be fine (many small cells per square inch) for lower coating weight jobs, for example UV coatings, or coarse (fewer large cells per square inch) for applying a protective coating or an adhesive coating to heavy stock.